Aspiration catheters have become common tools for use with embolic protection filters and angioplasty and stent placement catheter during intravascular interventional procedures. One challenge when using embolic protection filters is that the filters can become occluded due to overloading. This prevents the embolic filters from working, as flow is needed to bring particles into the filter, and creates visibility issues when radiopaque dye cannot flow through the vessel. It is also frequently desired to remove trapped emboli from embolic filters and from around occlusion balloons prior to removing these interventional tools so as to reduce the chance of any embolic debris from flowing downstream from the interventional site.
Aspiration is a potential method of removing these embolic particles from within filters and from around balloons, yet current aspiration catheters do not effectively remove the debris from these interventional devices due to the proximity, or rather lack of proximity, of the aspiration lumen when the aspiration catheter hits the proximal stop of the filter or proximal balloon skirt. Conventional aspiration catheters typically include a guide wire lumen running alongside of a guidewire lumen. The guidewire lumen is typically a short lumen at the distal end of the aspiration catheter, and the distal end of the aspiration lumen extends no farther than the distal end of the guidewire lumen. Therefore, when a widening of the embolic protection filter wire is reached, the aspiration catheter can be advanced no farther. Such a widening may be a strut, a stop or other feature of the embolic protection filter. Such features are commonly found proximal of the filter cavity. This prevents the distal end of the aspiration catheter from entering the filter cavity. However, one cannot extend a fixed aspiration lumen distal of the guide wire lumen without sacrificing the ability of the aspiration catheter to effectively track the guide wire or pass through narrowed body vessels.
What is desirable is a way to get the aspiration lumen distal of such stops and into proximity of the embolic debris to be removed without sacrificing trackability or crossability.